Methylmercury

Similar term(s): alkyl mercury, MeHg, methylmercury compounds.

Definition:

The term 'methylmercury' is commonly used as a generic term to describe (mono)methylmercury compounds. In fact,
methylmercury is not a compound in itself but a cation,
CH3Hg+, which forms one part of methylmercury compounds;
usually methylmercury salts.

Dimethylmercury is one methylmercury
compound that is not a salt. The methylmercury cation is normally associated
with either a simple anion, like chloride (Cl-), or a large
molecule (e.g. a
protein) with negative and positive
charges. The methylmercury cation is the most
toxic form of mercury, able to inhibit fetal
brain development, which results in the behavioural changes and reduced
cognitive and motor ability.

Source: GreenFacts

More:

Methylmercury is the most common form of
organic mercury found in the environment.
Environmental methylmercury arises from the methylation of
inorganic mercury by microorganisms in soil
and sediments, in air or under water. Some methylmercury compounds are used as
pesticides.